The 103 needs three wheels so that on take off you the nose has
something to roll on and when you land you need the tail wheel as you
will be touching down almost tail first close to stall speed. As you
decelerate, it rocks back over to the nose.

There was an earlier version of that glider with a retractable main gear
which was set further forward and no nose wheel. However, the rear seat
in that glider was very uncomfortable because it was very shallow (in
order to make room for the gear to retract. To solve that problem, the
main wheel was moved aft which necessitated the addition of a nose
wheel. This is somewhat a universal issue with 2 seaters and most have
a fixed or retractable nose wheel.

The Stemme S10 self launcher has retractable main gear (dual) and they
are set far enough apart to not need a wing runner. But for $250K, you
can find a lot of kids to run your wing and pay for a lot of tows.

As far as drag goes, the 103 is mostly used as a trainer. So it is not
that big a deal. Which brings up the final point. The 103 is somewhat
of a pig. Once you get your three friends to throw up, you will want a
nice single seat glider anyway.

Bob

Capt. Geoffrey Thorpe wrote:
First, I've been told, by someone that taught middle school, that whoever
said "there is no such thing as a stupid question" never taught middle
school... :-)

Second, I should confess up front that I don't fly or know that much about
gliders.

But... I was doing some virtual tire kicking over on the wingsandwheels.com
want ads and looking at a picture of a Grob 103 twin 3 Acro - thinking that
looks like it could be fun - and it hit me - this thing has three wheels.
Now, I've seen other gliders with the same arangement before, but this time
it just struck me as odd.

As I understand it, the "traditional" arangement is one main wheel near the
CG plus one tail wheel. The idea being that one wheel has half the weight
and half the drag drag compared to the two main wheels found on the typical
powered airplane - right?

But on the Grob, I see three, count-em, three wheels. Same number as the
Cessna 120 I learned to fly in oh so many years ago. But! Instead of putting
two wheels side by side so the airplane can stand up by itself (avoiding
need for wing runners, wheels strapped to the wing to move it from place to
place, and whatever else comes from having the wheel in the middle) this has
all three wheels in a row. Seems to me that this arrangement has all the
disadvantages (weight and drag) but none the advangages (able to stand up
unaided) of having all those wheels.

What's up with that?